Stapler
A stapler for stapling together a workpiece, primarily a sheaf of papers, in which the stapler comprises a stapling unit and an anvil, which interacts with the stapling unit and on which the workpiece is placed, and against which stapling is performed, which stapling unit and an anvil are, driven relative to each other in a reciprocating stapling movement, during which movement stapling takes place, the stapling unit comprises a frame and a staple cassette which houses staple blanks and which is exchangeable, and which is detachably connected to the frame by attachment devices, and the staple blanks are fed one by one to an outlet channel by a feeding device incorporated in the stapler.
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The present invention relates to a stapler for stapling together a workpiece, primarily a sheaf of papers, in which the stapler comprises a stapling unit and an anvil which interacts with the stapling unit and on which the workpiece is placed, and against which stapling is performed, which stapling unit and anvil are driven by means of a drive means in a reciprocating stapling movement relative to each other, during which movement stapling takes place, wherein the stapling unit comprises a frame and a staple cassette which houses staple blanks and which is exchangeable, and which is detachably connected to the frame by attachment devices, wherein the staple blanks are fed one by one to an outlet channel by a feeding device incorporated in the stapler, through which outlet channel a staple which has been fed and formed into staple shape during the stapling movement is driven by a blade-shaped driver incorporated in the stapler to staple the workpiece, which driver is driven by the drive means and acts on the staple crown, wherein the outlet channel is, in the direction which is transverse to the longitudinal direction of the staple crown, defined by a first guide surface provided with a first face disposed on the staple cassette and a second guide surface provided with a second face disposed on the frame, which faces guide the staple as it is driven through the outlet channel, the clearance between the faces of the outlet passage being determined by spacing elements.
STATE OF THE ARTStaplers of the type described above have long been known and commonly existed. The applicant's own, earlier patent, U.S. Pat. No. 5,794,833, which shows an apparatus of this type in all essential respects, may be cited as just one example.
However, the disadvantage of earlier apparatuses is that the use of releasable fasteners to attach the staple cassette to the frame may, due to manufacturing tolerances, easily cause failure of the fasteners to attach the cassette securely to the frame, with the result that the distance between the faces of the outlet passage may be bigger than that permitted by the spacing elements, causing the driver, when driving the staple, to lose grip with the staple crown, with the result that the staple is not driven sufficiently into the workpiece, leading to failure to achieve satisfactory stapling or, in the worst case, no stapling whatever. Since the location of the outlet channel is such that is not visible, the fault cannot be observed and corrected before stapling is carried out and, if faulty stapling is discovered, it is impossible to ascertain with certainty that that the fault is due to a faulty outlet channel since this can be observed only with great difficulty.
ProblemThus, there exists a need for a stapler of the type described above in which the first and the second guide surfaces are maintained in a position such that the distance between them does not exceed that determined by the spacing elements and which distance is maintained even if greater manufacturing tolerances occur in the component parts.
SolutionThe present invention provides a solution to the aforementioned problems by means of a stapler of the type described above, which is characterised in that the guide surfaces are movable toward and away from each other relative to each other and that they are pressed toward each other using one or more elastic elements.
The present invention is also characterised in that the second guide surface is movable in a direction toward and away from the first guide surface and that it is moved toward the first guide surface by incorporated elastic means when the staple cassette is fitted to the frame.
The present invention is further characterised in that the second guide surface is, when the staple cassette is not attached, moved by included elastic means ahead of the position in which it is located when the staple cassette is attached.
The present invention is further characterised in that the incorporated elastic means consist of helical springs.
The present invention will hereinafter be described with reference to the appended figures, of which:
The anvil surface and stapling unit are, in known manner, connected by connecting means which are not shown in the figure, but which enable the anvil and stapling unit to be moved toward and away from each other in a reciprocating stapling movement, which movement is indicated by the double arrow P. The connecting means may consist of parts included in the equipment to which the stapler is attached or may be part of the stapler. The stapling movement is achieved using a drive means 4, which comprises an electric motor 5 connected to the stapling unit 3 by a transmission shaft 6. It will be clear to one skilled in the art that the electric motor 5 may also be integrated in the stapling unit. The figure also shows the workpiece 7 to be stapled, the said workpiece being placed on the anvil 2 against which stapling is performed.
The construction of the frame 8 is shown in greater detail in
The function of the forming punch 44, driver 45 and feeding device 13 will be described with reference to
In
Claims
1. A stapler for stapling together a workpiece, comprising:
- a stapling unit; and
- an anvil, which interacts with the stapling unit, on which the workpiece is placed, and against which stapling is performed,
- the stapling unit and the anvil being driven relative to each other in a reciprocating stapling movement by a drive mechanism, during which movement stapling takes place,
- wherein the stapling unit includes a frame and a staple cassette, the staple cassette housing staple blanks, being exchangeable, and being detachably attached to the frame by attachment devices,
- wherein the staple blanks are fed one by one to an outlet channel by a feeding device incorporated in the stapler, a staple which has been fed and formed into staple shape during the stapling movement being driven through the outlet channel by a blade-shaped driver so as to staple the workpiece, the driver being driven by drive links driven by the drive mechanism and acting on a crown of the formed staple,
- wherein the outlet channel is, in a direction which is transverse to a longitudinal direction of the crown of the formed staple, defined by a first guide surface and a second guide surface, the first guide surface having a first face disposed on the staple cassette, the second guide surface having a second face disposed on the frame, the first and second faces guiding the formed staple as it is driven through the outlet channel, a clearance between the first and second faces being determined by spacing elements,
- wherein at least one of the first and second guide surfaces is movable toward and away from the other of the first and second guide surfaces and is biased toward the other by one or more elastic elements.
2. A stapler according to claim 1, wherein the second guide surface is movable toward and away from the first guide surface and is biased toward the first guide surface by the one or more elastic elements.
3. A stapler according to claim 2, wherein when the staple cassette is detached from the frame, the second guide surface is biased by the one or more elastic elements to a different position from that in which it is located when the staple cassette is attached to the frame.
4. A stapler according to claim 3, wherein the one or more elastic elements include a helical spring.
5. A stapler according to claim 2, wherein the one or more elastic elements include a helical spring.
6. A stapler according to claim 1, wherein when the staple cassette is detached from the frame, the second guide surface is biased by the one or more elastic elements to a different position from that in which it is located when the staple cassette is attached to the frame.
7. A stapler according to claim 3, wherein the one or more elastic elements include a helical spring.
8. A stapler according to claim 1, wherein the one or more elastic elements include a helical spring.
9. A stapling unit comprising:
- a frame; and
- a staple cassette, which holds staple blanks and is releasably attached to the frame so as to be replaceable, the staple blanks being fed from the staple cassette to an outlet channel,
- the outlet channel guiding a formed staple blank to a workpiece to be stapled during a stapling motion and being formed by a surface of the staple cassette and a surface of the frame opposed thereto,
- wherein at least one of said surface of the staple cassette and said surface of the frame is elastically biased toward the other, and a minimum distance between said surface of the staple cassette and said surface of the frame is set by one or more spacers.
10. A stapling unit according to claim 9, wherein said surface of the frame is elastically biased toward said surface of the staple cassette.
11. A stapling unit according to claim 9, wherein the one or more spacers are arranged between said surface of the frame and said surface of the staple cassette.
12. A stapling unit according to claim 9, wherein said surface of the staple cassette and said surface of the frame are maintained at said minimum distance throughout the stapling motion.
13. A stapling unit according to claim 9, wherein the frame includes a forming block constructed to shape staple blanks, and said surface of the frame includes at least a portion of the forming block.
14. A stapling unit according to claim 13, wherein the forming block is biased toward the staple cassette.
15. A stapling unit according to claim 13, wherein the forming block is moveable independent of other portions of the frame.
16. A stapling unit according to claim 9, wherein said surface of the stapling cassette includes a front plate of the stapling cassette.
17. A stapling unit according to claim 16, wherein the one or more spacers includes guide strips formed on the front plate so as to guide the formed staple laterally when the formed staple is driven through the outlet channel during the stapling movement.
18. A stapler for stapling together a workpiece, the stapler comprising:
- a frame constructed to releasably support a staple cassette, which holds staple blanks, such that an outlet channel is formed by a surface of the frame and an opposing surface of the staple cassette, the outlet channel guiding a formed staple blank to the workpiece during a stapling motion,
- wherein said surface of the frame is elastically biased toward said opposing surface of the staple cassette when the staple cassette is supported by the frame, and
- a forming block is biased toward said opposing surface of the staple cassette.
19. A stapler according to claim 18, wherein the frame includes the forming block, which is constructed to shape staple blanks, and said surface of the frame includes at least a portion of the forming block.
20. A stapler according to claim 18, further comprising an anvil constructed to support the workpiece during the stapling motion and against which stapling of the workpiece is performed.
21. A stapler according to claim 20, further comprising a drive mechanism adapted to drive the frame and the anvil relative to each other in a reciprocating stapling motion.
22. A stapler according to claim 18, further comprising a staple feeding device adapted to feed staple blanks from a staple cassette supported by the frame toward the outlet channel.
23. A stapler according to claim 18, further comprising a staple driver adapted to drive a formed staple through the outlet channel so as to staple the workpiece.
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Type: Grant
Filed: Apr 13, 2005
Date of Patent: Jun 1, 2010
Patent Publication Number: 20080265000
Assignee: Isaberg Rapid AB (Hestra)
Inventors: Ulf Jönsson (Hyltebruk), Lars-Inge Magnusson (Hestra), Frank Ambjörnsson (Hestra), Trygve Gustavsson (Asenhöga)
Primary Examiner: Rinaldi I. Rada
Assistant Examiner: Nathaniel Chukwurah
Attorney: Miles & Stockbridge P.C.
Application Number: 11/579,443
International Classification: B25C 5/15 (20060101);